Or grab the CR type whiz wheel in your shirt pocket & have the answer in a second or two...
I've used my whiz wheel more times than I can count. Not just for standard, accurate time/dist/fuel calcs inflight. Also for:
* Reach (position/altitude) by (time/place) ATC instructions
* Lose x minutes by (position) ATC instructions
* actual wind from drift/TAS/GS (several times over a period to gauge trend) to use for an accurate in flight range calculation after calculating max. allowable headwind/min. required tailwind before a diversion is mandatory.
*PNRs & CP/equitime points
* fuel to load at next landing to ensure a certain amount of capacity at a subsequent refuel point.
* conversion functions eg fuel amounts, pax questions about where/when/time stuff.
* finding alon- track groundspeed using an off-track DME (need a CR for this, not a slide type.